1. Field of the Invention
The invention relates to a method for descaling a metal strip, wherein the metal strip is guided in a transport direction from a forward roll stand to a rearward roll stand, wherein a descaling liquid is sprayed from a working distance onto the metal strip by means of a descaling device between the roll stands, wherein the metal strip, at the level of the descaling device, is deflected by a forced deflection amount in a direction transverse to the transport direction by means of an advancing element. The invention further relates to a corresponding descaling arrangement.
2. Description of the Related Art
When hot-rolling a metal strip, in particular, a steel strip, a scale layer is formed on the metal strip after rolling. This scale layer must be removed in order to be able to produce a metal strip of high-quality. In the prior art, a descaling liquid, in general, water, is sprayed from a working distance under high-pressure onto the metal strip by means of a descaling device.
Metal strips are conventionally rolled in multi-stand roll lines. Between the individual roll stands the metal band is subjected to tension which is to be maintained as constant as possible. Between the two roll stands a looper is conventionally arranged for the purpose of maintaining a constant tension. When advancing the looper against the metal strip, the metal strip is deflected in a direction transverse to the transport direction. In order to prevent the metal strip from contacting the descaling device when being deflected, the descaling device in the prior art is therefore arranged at a relatively large working distance from the metal strip. Moreover, upon deflection of the metal strip the working distance changes. This results in a reduced and non-uniform impact on the metal strip.
From German patent document 195 35 789 C2 a descaling method is known in which the actual distance of the descaling device from the metal strip is detected and the position of the descaling device is controlled such that the actual spacing is substantially maintained at a constant level.
In another German patent application 198 17 002.5, which was not yet published at the time of filing of the priority application of the instant application, a descaling method for a metal strip is disclosed in which the strip profile is determined and the descaling device is adjusted according to the detected course of the profile.